In communication networks, such as telecommunication networks, a call or a service often involves, on the one hand, a control plane or signalling plane and, on the other hand, a user plane or media plane. The control plane or signalling plane is concerned with connection management. The user plane or media plane is mainly in charge of transporting the user data.
In this context, network operators often want to define and enforce a set of rules in the network. A set of rules constitutes policies. A policy framework for managing and enforcing these policies usually includes at least three elements, or functions: a policy repository for storing the policy rules, which may be user-specific, a policy decision element, function or point, and a policy enforcement element, function or point. The purposes of a policy framework include controlling subscriber access to the networks and services.
A policy framework notably addresses the decisions as to whether the subscriber, i.e. the user, is entitled, or authorized, to enjoy a service, and whether the network can provide the service to the subscriber (and, possibly, with which quality of service).
Policy and charging control (PCC) architectures, such as, but not limited to, the architecture described in “3GPP TS 23.203 V11.6.0 (2012-06); Technical Specification; 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Policy and charging control architecture (Release 11)” (available on http:www.3gpp.org/ftp/Specs/html-info23203.htm) (hereinafter referred to as “reference [1]”), integrate the policy and charging control.
In such a PCC architecture, the policy and charging rules function (PCRF) is a functional entity in charge of deciding charging, policies and quality of service (QoS) for services of a given user. The PCRF may for example decide the quality of the connection to be allocated for voice, video, etc., which results, for example, on the establishment of dedicated bearer(s) with guaranteed bit rate (GBR) or non-guaranteed bit rate (non GBR). The PCRF may also make decisions about packet forwarding treatment in the radio access network (RAN) by means of determining the QoS class identifier (QCI). The PCRF may also decide, at the packet core control plane, the priority of a bearer to be established over other bearers, for the same or different users. Based on the above decisions by the PCRF, PCC rules may be generated and then installed in a policy and charging enforcement function (PCEF) of the PCC architecture, so that each service is given the appropriate treatment that the service requires. Installing PCC rules from the PCRF in the PCEF may include the PCRF generating the PCC rules, downloading and activating said PCC rules to the PCEF, or may include activating, from the PCRF, indicated PCC rules configured in the PCEF.
The background further includes the following documents.
3GPP TR 29.816 V10.0.0 (2010-09), “Technical Report; 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Study on PCRF failure and restoration (Release 10)”, hereinafter referred to as reference [2], contains the results of a study on PCRF failure and restoration, with a discussion of various scenarios (clause 4), functional requirements for solutions (clause 5), and different solutions (clause 6).
3GPP TS 23.335 V10.0.0 (2011-03), “Technical Specification, 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; User Data Convergence (UDC); Technical realization and information flows; Stage 2 (Release 10)”, hereinafter referred to as reference [3], relates to procedures and signalling flows associated with a user data convergence (UDC) concept supporting a layered architecture separating the data from the application logic in a telecommunication system. In particular, user data may be stored in a logically unique repository allowing access from core and service layer entities.
WO 2011107813 A1, hereinafter referred to as reference [4], relates to handling redundancy of a PCRF in a wireless communication network having an active PCRF, a standby PCRF and a PCEF by replicating accumulative quota usage of the active PCRF in a memory of the standby PCRF every time an update request is received at the active PCRF.
WO 2012095697 A1, hereinafter referred to as reference [5], relates to a PCC architecture with an autonomous PCRF redundancy, in which a standby PCRF may replace a formerly active PCRF by obtaining from each PCRF client the dynamic data currently applying to existing IP-CAN sessions.
It is desirable to provide methods and apparatuses to improve PCC architectures and implementations, notably by providing efficient failover mechanisms as well as scalable architectures, without increasing, or at least without excessively increasing, the implementation and architecture complexity and the associated equipment costs.